#include <iostream>
using namespace std;
class AB{
private:
	int a;
	int b;
public:
	AB(int a=0,int b=0):a(a),b(b){}
	void seta(int a){this->a=a;}
	void setb(int b){this->b=b;}
	void show(){
		cout << "面积=" <<  a*b << endl;
	}
};
class AA:public AB{
private:
	void setb(int a){}
public:
	AA(int a):AB(a,a){}
	void seta(int a){
		AB::seta(a);
		AB::setb(a);
	}
};
int main()
{
	AA temp1(5);
	temp1.show();
	temp1.seta(6);
	temp1.show();
	return 0;
}
